[wengang1]

Hi all.
I posted a while back about 3 switches one light. Well I have another such setup in my house, old work, and I need some clarification on this one.
I'm posting a diagram of what I followed last time, for reference.

Looking at the wiring in this old work, it looks similar to the diagram, but the difference is: The diagram shows power going to the light, then to the 3-way switch then 4way then the last 3way.
My wiring appears to show the power going to the light and the first switch at the same time, terminating on one end at the light, and then from that 3way on to the 4way and the terminal 3way.

Is this possible? It was a double-gang box with two switches (the other for a porch light), and there was only one hot wire coming in which appeared to pigtail a hot wire to the 3way switch. Anyway, the box was so cluttered with wires (5) that I disassembled it all. If necessary, I can always run a hot line up from the box to the light and then back down to the 3way switch to recreate the attached diagram that I can get my mind around, but I know the switch was working the way it was wired before, so it seems unnecessary.

Why did I mess with it to begin with? In the course of drywall prep, I put in new light boxes (didn't mess with any switches), and when I turned the power back on after the drywall was up, the light was permanently on. Previously this was a ceiling fan and the wire running to it was 14/3. I used that same wire and just ignored the red when I attached my light. From there, I opened up the box to see why the light wouldn't turn off.

To summarize, how could the light be terminal in this 3-4-3 configuration with power going to the first switch and the light at the same time?

 

[joed]

My wiring appears to show the power going to the light and the first switch at the same time,

Not sure I understand this. Does power go the light or the switch? Do you mean power and light both connect to the switch?
It is possible to have power going to any of the switches and the light connected at any of the switches.

 

[AllanJ]

You have the power cable entering the light fixture box. From there the raw hot conductor should be wired all the way to the furthest switch box using white* wires or alternatively the switched hot from the light fixture wired to the furthest switch box using all black wires.

White from the power feed cable is connected to white going to the light without first going out to the switches and coming back.

A white* wire connected to a colored wire or connected to a switch terminal should be marked with a band of black tape or stain at both ends.

Color rules differ for those (usually newer) installations where neutral has to go out to the switch boxes. For this kind of installation, the same wire, white, is used for neutral both going out to the switches and coming back.

 

[wengang1]

From what I could tell before I disassembled it all, the hot wire came into the box and the black wires from all the other wires were twisted together, one of those black went to the light, another went to the 3way switch, another went to a different switch (porch light) and another went to an outgoing line that I haven't tracked down. One last black wire was pigtailed from the wirenut to the porch light switch. All the white wires were twisted together from all the lines, with one wire going out to the 3way switch. I couldn't say any more clearly than that. I've never seen so much wire packed into such a tight space. I had to start untwisting before I had the full picture in order to be able to disentangle some of the wires.

I'm not worried about putting the porch light switch back together or continuing that other outbound line. As for the 3-way switch and the light, I know I can split that one hot wire and run that up to the light, then proceed to rewire based on the attached diagram. I was just wondering how the last guy got this to work with the light being terminal and the second 3-way also being terminal, and the incoming power seemingly twisted together with the first 3-way and the wire going to the light.

I also didn't understand why my light was permanently on after I merely used the 14/3 wire already in the light box to connect the light with white and black, and left the red wire hanging free. And for that matter, I don't know why a 14/3 wire was run to the light. When the ceiling fan was there, the red wire went to a blue wire on the fan, but with a cheap placeholder light fixture, there is only a place for black and white wires.

 

[seharper]

I don't even try to understand Egyptian spaghetti like that. (black red white gold). I consider that "making it unnecessarily hard". Life goes easier if you just color code your wires by their function.

Yellow = travelers
Red = switched-hot

Draw a box for lamp and each switch, then draw the cable coming in from supply with black and white wire. Then draw some "cable" between the boxes as they are actually cabled, just draw 2 lines with some space between them and we'll draw in wires later, and we'll color code the wires by function.


From the 3-way, through the 4-way and to the other 3-way, draw TWO YELLOW wires. Two. Yellow are travlers and there are 2.

Draw 1 black wire from supply to either of the switches. Black is always-hot.

Draw 1 white wire from supply to the lamp. Also to the switch that got black because of NEC 2011 Code. White is neutral.

Draw 1 red wire from the *other* 3-way switch to the lamp. Red is switched-hot.


Now, most of the time, you find there are 3 wires in most of these "cables". And everything "just works out".

Often, you can correct things just by rearranging components. For instance putting the 4-way in the wrong place will create a LOT of work and unnecessary wires.

Sometimes, though, your best efforts reach an impasse.

Sometimes you find 4 wires in a cable - often relating to that NEC 2011 neutral we ran to a switch. You can either violate Code at this point and omit it, or use the correct /4 cable. And by "can" I mean you'll get written up by the inspector and have to fix it.

If you find 5 wires in a cable, then it's time for smurf tube and THHN.

When you get to actually installing it, when white is not neutral it MUST be re-marked and must be used for always-hot if that is present. Feel free to use colored electrical tape to re-mark everything else by function. Always mark both ends of a wire the same. It really does make life easier.

 

[joed]

I also didn't understand why my light was permanently on after I merely used the 14/3 wire already in the light box to connect the light with white and black, and left the red wire hanging free.

Because the red wire was probably the switched wire that needed to be connected to the light black wire.

 

[wengang1]

So, to simplify, I rewired it entirely to precisely match the diagram I originally posted. No joy. The light does not come on. I tested the bulb in another socket, ok.

I have a simple tester with red and black probes, when it goes red to black and black to ground, it tells me 120. I tested at every point along the way, and black and ground are saying 120 all the way to the final switch, but the light is staying off.

Next thing to try? Thanks.

 

[wengang1]

Just to follow up, I took the tester and tried it out on the 4-way switch (see my diagram). When the switch is flipped one way, the ground and either screw on the left shows 120 (the white wires). When I flip the switch the other way, the top white shows 120 and the bottom right shows 120. At no point does the top right (red) ever show 120. I think I have the connections exactly right. Is something switched around?

 

[joed]

I would remove the four way and connect the two red together and the two whites together. Then test the three ways. When you get that working then install the four way.

 

[wengang1]

OK. Did as you said and the two 3ways work as expected. What now?

 

[RAL238]

If you had things wired as in the diagram, with both red wires on one side, and both white wires on the other side, try connecting it so the red and white wires from one cable connect to one side of the switch, and the red and white wires from the other cable connect to the other side of the switch.

 

[joed]

That means you have not identified the proper pairing on the four way. There should be two sets of coloured screws. The red and white from one cable goes to one pair and the red and white from the second cable goes to the other pair.

or the four way is defective.

 

[wengang1]

So what I have now is the two 3way switches work as expected in all cases, but the if either 3way swtich is toggled to one of the two positions, the 4way switch stops working, and if they are toggled to their other position, the 4way works as expected.

 

[joed]

Does the four way have two screws different colour than the other two?

 

[RAL238]

So what I have now is the two 3way switches work as expected in all cases, but the if either 3way swtich is toggled to one of the two positions, the 4way switch stops working, and if they are toggled to their other position, the 4way works as expected.

Your description points to the 4-way switch being wired incorrectly. Did you try switching the wires as described in the earlier post?

 

[wengang1]

Yes, the first configuration was as shown in the diagram. No light. Then I tried putting the wires from each cable on either side of the switch. That resulted in the strange behavior I described.

Just now I went and switched it back to reds on one side, white on the other, same cable on same color screws. It works fine. All I can figure is that I looked at it crosseyed this afternoon and had two wires switched.

Thanks for you help , all.